946 resultados para Early Development


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The study of convergence and divergence in global economy and social development utilises comparative indicators to investigate the contents of economic and social development policy and their effects on the global samples that represent the rich industrial, semi-industrial and the poor developing nations. The study searchesfor answers to questions such as "what are the objectives of economic growth policies in globalisation under the imperatives of convergence and divergence, and how do these affect human well-being in consideration to the objectives of social policy in various nations?" The empirical verification of data utilises the concepts of the `logic of industrialism´ for comparative analysis that focuses mainly on identifying the levels of well-being in world nations after the Second World War. The perspectives of convergence and divergence in global economy and social development critically examine the stages of early development processes in global economy, distinguish the differences between economy and social development, illustrate the contents of economic and social development policies, their effects on rich and poor countries, and the nature of convergence and divergence in propelling economic growth and unequal social development in world nations. The measurement of convergence and divergence in global economy and social development utilised both economic and social data that were combined into an index that measures the precise levels of the effects of economic and social development policies on human well-being in the rich and poor nations. The task of finding policy solutions to resolve the controversies are reviewed through empirical investigations and the analyses of trends indicated within economic and social indicators and data. These revealed how the adoption of social policy measures in translating the gains from economic growth, towards promoting education, public health, and equity, generate social progress and longer life expectancy, higher economic growth, and sustain more stable macro economy for the nations. Social policy is concerned with the translation of benefits from objectives of global economic growth policies, to objectives of social development policy in nation states. Social policy, therefore, represents an open door whereby benefits of economic growth policies are linked with the broader objectives of social development policy, thereby enhancing the possibility of extending benefits from economic growth to all human being in every nation.

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In development of human medicines, it is important to predict early and accurately enough the disease and patient population to be treated as well as the effective and safe dose range of the studied medicine. This is pursued by using preclinical research models, clinical pharmacology and early clinical studies with small sample sizes. When successful, this enables effective development of medicines and reduces unnecessary exposure of healthy subjects and patients to ineffectice or harmfull doses of experimental compounds. Toremifene is a selective estrogen receptor modulator (SERM) used for treatment of breast cancer. Its development was initiated in 1980s when selection of treatment indications and doses were based on research in cell and animal models and on noncomparative clinical studies including small number of patients. Since the early development phase, the treatment indication, the patient population and the dose range were confirmed in large comparative clinical studies in patients. Based on the currently available large and long term clinical study data the aim of this study was to investigate how the early phase studies were able to predict the treatment indication, patient population and the dose range of the SERM. As a conclusion and based on the estrogen receptor mediated mechanism of action early studies were able to predict the treatment indication, target patient population and a dose range to be studied in confirmatory clinical studies. However, comparative clinical studies are needed to optimize dose selection of the SERM in treatment of breast cancer.

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The aim of the present study was to compare the toxic effects of fluoxetine (F) (8 and 16 mg/kg) and venlafaxine (V) (40 and 80 mg/kg) administered during the third week of pregnancy on early development of rats. Both antidepressants were administered by gavage on pregnancy days 15 to 20 to groups of 10 to 12 animals each. Duration of gestation, food and water consumption, number of live pups and birth weight were recorded. Litters were culled to six pups at birth (day 1) and followed for growth until weaning (day 25). On day 60, a male and a female from each litter were injected with the 5-HT1 agonist, 5-methoxy-N,N-dimethyltryptamine (6 mg/kg, ip) and the serotonergic syndrome was graded. Fluoxetine but not venlafaxine reduced the duration of pregnancy when compared to the control (C) group (F = 21.1 days and C = 21.6 days, mean, P<0.02; maximum = 22 days and minimum = 21 days in both groups). The highest doses of both fluoxetine, 16 mg/kg (F16), and venlafaxine, 80 mg/kg (V80), reduced the food intake of pregnant rats, resulting in different rates of body weight gain during treatment (from pregnancy day 15 to day 20): F16 = 29.0 g, V80 = 28.7 g vs C = 39.5 g (median). Birth weight was influenced by treatment and sex (P<0.05; two-way ANOVA). Both doses of fluoxetine or venlafaxine reduced the body weight of litters; however, the body weight of litters from treated dams was equal to the weight of control litters by the time of weaning. At weaning there was no significant difference in weight between sexes. There was no difference among groups in number of live pups at birth, stillbirths, mortality during the lactation period or in the manifestation of serotonergic syndrome in adult rats. The occurrence of low birth weight among pups born to dams which did not show reduced food ingestion or reduction of body weight gain during treatment with lower doses of fluoxetine or venlafaxine suggests that these drugs may have a deleterious effect on prenatal development when administered during pregnancy. In addition, fluoxetine slightly but significantly affected the duration of pregnancy (about half a day), an effect not observed in the venlafaxine-treated groups.

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We studied the effects of the acute administration of small doses of lead over time on hemodynamic parameters in anesthetized rats to determine if myocardial contractility changes are dependent or not on the development of hypertension. Male Wistar rats received 320 µg/kg lead acetateiv once, and their hemodynamic parameters were measured for 2 h. Cardiac contractility was evaluated in vitro using left ventricular papillary muscles as were Na+,K+-ATPase and myosin Ca2+-ATPase activities. Lead increased left- (control: 112 ± 3.7 vs lead: 129 ± 3.2 mmHg) and right-ventricular systolic pressures (control: 28 ± 1.2vs lead: 34 ± 1.2 mmHg) significantly without modifying heart rate. Papillary muscles were exposed to 8 µM lead acetate and evaluated 60 min later. Isometric contractions increased (control: 0.546 ± 0.07 vs lead: 0.608 ± 0.06 g/mg) and time to peak tension decreased (control: 268 ± 13vs lead: 227 ± 5.58 ms), but relaxation time was unchanged. Post-pause potentiation was similar between groups (n = 6 per group), suggesting no change in sarcoplasmic reticulum activity, evaluated indirectly by this protocol. After 1-h exposure to lead acetate, the papillary muscles became hyperactive in response to a β-adrenergic agonist (10 µM isoproterenol). In addition, post-rest contractions decreased, suggesting a reduction in sarcolemmal calcium influx. The heart samples treated with 8 µM lead acetate presented increased Na+,K+-ATPase (approximately 140%, P < 0.05 for control vs lead) and myosin ATPase (approximately 30%, P < 0.05 for control vs lead) activity. Our results indicated that acute exposure to low lead concentrations produces direct positive inotropic and lusitropic effects on myocardial contractility and increases the right and left ventricular systolic pressure, thus potentially contributing to the early development of hypertension.

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Considerable research has focused on the success of early intervention programs for children. However, minimal research has focused on the effect these programs have on the parents of targeted children. Many current early intervention programs champion family-focused and inclusive programming, but few have evaluated parent participation in early interventions and fewer still have evaluated the impact of these programs on beliefs and attitudes and parenting practices. Since parents will continue to play a key role in their child's developmental course long after early intervention programs end, it is vital to examine whether these programs empower parents to take action to make changes in the lives of their children. The goal of this study was to understand parental influences on the early development of literacy, and in particular how parental attitudes, beliefs and self efficacy impact parent and child engagement in early literacy intervention activities. A mixed method procedure using quantitative and qualitative strategies was employed. A quasi-experimental research design was used. The research sample, sixty parents who were part of naturally occurring community interventions in at- risk neighbourhoods in a south-western Ontario city participated in the quantitative phase. Largely individuals whose home language was other than English, these participants were divided amongst three early literacy intervention groups, a Prescriptive Interventionist type group, a Participatory Empowering type group and a drop-in parent- child neighbourhood Control group. Measures completed pre and post a six session literacy intervention, on all three literacy and evidence of change in parental empowerment. Parents in all three groups, on average, held beliefs about early literacy that were positive and that were compatible with current approaches to language development and emergent literacy. No significant change in early literacy beliefs and attitudes for pre to post intervention was found. Similarly, there was no significant difference between groups on empowerment scores, but there was a significant change post intervention in one group's empowerment score. There was a drop in the empowerment score for the Prescriptive Interventionist type group, suggesting a drop in empowerment level. The qualitative aspect of this study involved six in-depth interviews completed with a sub-set of the sixty research participants. Four similar themes emerged across the groups: learning takes place across time and place; participation is key; success is achieved by taking small steps; and learning occurs in multiple ways. The research findings have important implications for practitioners and policy makers who target at risk populations with early intervention programming and wish to sustain parental empowerment. Study results show the value parents place on early learning and point to the importance of including parents in the development and delivery of early intervention programs. groups, were analyzed for evidence of change in parental attitudes and beliefs about early literacy and evidence of change in parental empowerment. Parents in all three groups, on average, held beliefs about early literacy that were positive and that were compatible with current approaches to language development and emergent literacy. No significant change in early literacy beliefs and attitudes for pre to post intervention was found. Similarly, there was no significant difference between groups on empowerment scores, but there was a significant change post intervention in one group's empowerment score. There was a drop in the empowerment score for the Prescriptive Interventionist type group, suggesting a drop in empowerment level. The qualitative aspect of this study involved six in-depth interviews completed with a sub-set of the sixty research participants. Four similar themes emerged across the groups: learning takes place across time and place; participation is key; success is achieved by taking small steps; and learning occurs in multiple ways. The research findings have important implications for practitioners and policy makers who target at risk populations with early intervention programming and wish to sustain parental empowerment. Study results show the value parents place on early learning and point to the importance of including parents in the development and delivery of early intervention programs.

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Many aspects of early embryonic development in the horse are unusual or unique; this is of scientific interest and, in some cases, considerable practical significance. During early development the number of different cell types increases rapidly and the organization of these increasingly differentiated cells becomes increasingly intricate as a result of various inter-related processes that occur step-wise or simultaneously in different parts of the conceptus (i.e., the embryo proper and its associated membranes and fluid). Equine conceptus development is of practical interest for many reasons. Most significantly, following a high rate of successful fertilization (71-96%) (Ball, 1988), as many as 30-40% of developing embryos fail to survive beyond the first two weeks of gestation (Ball, 1988), the time at which gastrulation begins. Indeed, despite considerable progress in the development of treatments for common causes of sub-fertility and of assisted reproductive techniques to enhance reproductive efficiency, the need to monitor and rebreed mares that lose a pregnancy or the failure to produce a foal, remain sources of considerable economic loss to the equine breeding industry. Of course, the potential causes of early embryonic death are numerous and varied (e.g. persistent mating induced endometritis, endometrial gland insufficiency, cervical incompetence, corpus luteum (CL) failure, chromosomal, genetic and other unknown factors (LeBlanc, 2004). However, the problem is especially acute in aged mares with a history of poor fertility in which the incidence of embryonic loss between days 2 and 14 after ovulation has been reported to reach 62-73%, and in which embryonic death is due primarily to embryonic defects rather than to uterine pathology (Ball et al., 1989; Carnevale & Ginther, 1995; Ball, 2000).

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Objectives To investigate whether sleep disturbances previously found to characterise high risk infants: (a) persist into childhood; (b) are influenced by early maternal settling strategies and (c) predict cognitive and emotional/behavioural functioning. Methods Mothers experiencing high and low levels of psychosocial adversity (risk) were recruited antenatally and longitudinally assessed with their children. Mothers completed measures of settling strategies and infant sleep postnatally, and at 12 and 18 months, infant age. At five years, child sleep characteristics were measured via an actigraphy and maternal report; IQ and child adjustment were also assessed. Results Sleep disturbances observed in high-risk infants persisted at five years. Maternal involvement in infant settling was greater in high risk mothers, and predicted less optimal sleep at five years. Poorer five year sleep was associated with concurrent child anxiety/depression and aggression, but there was limited evidence for an influence of early sleep problems. Associations between infant/child sleep characteristics and IQ were also limited. Conclusions Early maternal over-involvement in infant settling is associated with less optimal sleep in children, which in turn, is related to child adjustment. The findings highlight the importance of supporting parents in the early development of good settling practices, particularly in high-risk populations.

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The aim of this paper is to examine the acquisition pattern of person and number verb morphology within the generative framework and to compare the results of the analyses with previous research in Greek and other European languages. The study considers previous data on the acquisition of subject-verb agreement, and thereafter, examines the acquisition of person and number morphology in a new dataset of two monolingual Greek-speaking children. The analyses present quantitative data of accuracy of person and number marking, error data, and qualitative analyses addressing the productivity of person and number marking. The results suggest that person and number morphology is used correctly and productively from a very early age in Greek speaking children. The findings provide new insight into early Greek language acquisition and are also relevant for research in early development of languages with rich inflectional morphology.

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Although cloning of mammals has been achieved successfully, the percentage of live offspring is very low because of reduced fetal size and fewer implantation sites. Recent studies have attributed such pathological conditions to abnormal reprogramming of the donor cell used for cloning. The inability of the oocyte to fully restore the differentiated status of a somatic cell to its pluripotent and undifferentiated state is normally evidenced by aberrant DNA methylation patterns established throughout the genome during development to blastocyst. These aberrant methylation patterns are associated with abnormal expression of imprinted genes, which among other genes are essential for normal embryo development and gestation. We hypothesized that embryo loss and low implantation rates in cattle derived by somatic cell nuclear transfer (SCNT) are caused by abnormal epigenetic reprogramming of imprinted genes. To verify our hypothesis, we analyzed the parental expression and the differentially methylated domain (DMD) methylation status of the H19 gene. Using a parental-specific analysis, we confirmed for the first time that H19 biallelic expression is tightly associated with a severe demethylation of the paternal H19 DMD in SCNT embryos, suggesting that these epigenetic anomalies to the H19 locus could be directly responsible for the reduced size and low implantation rates of cloned embryos in cattle.

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The extensive replication of mitochondria during oogenesis and the wide variability in mitochondrial DNA ( mtDNA) copy numbers present in fully grown oocytes indicate that mtDNA amount may play an important role during early embryogenesis. Using bovine oocytes derived from follicles of different sizes to study the influence of mtDNA content on development, we showed that oocytes obtained from small follicles, known to be less competent in developing into blastocysts, contain less mtDNA than those originating from larger follicles. However, because of the high variability in copy number, a more accurate approach was examined in which parthenogenetic one-cell embryos were biopsied to measure their mtDNA content and then cultured to assess development capacity. Contrasting with previous findings, mtDNA copy number in biopsies was not different between competent and incompetent embryos, indicating that mtDNA content is not related to early developmental competence. To further examine the importance of mtDNA on development, one-cell embryos were partially depleted of their mtDNA (64% +/- 4.1% less) by centrifugation followed by the removal of the mitochondrial-enriched cytoplasmic fraction. Surprisingly, depleted embryos developed normally into blastocysts, which contained mtDNA copy numbers similar to nonmanipulated controls. Development in depleted embryos was accompanied by an increase in the expression of genes (TFAM and NRF1) controlling mtDNA replication and transcription, indicating an intrinsic ability to restore the content of mtDNA at the blastocyst stage. Therefore, we concluded that competent bovine embryos are able to regulate their mtDNA content at the blastocyst stage regardless of the copy numbers accumulated during oogenesis.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The effects of different feeding schemes on pacu Piaractus mesopotamicus early development were evaluated with respect to growth, survival, muscle development, and differential gene expression of MyoD and myogenin. The pacu larvae (4 days post hatch-dph, 0.77 mg wet weight) were given six feeding treatments intentionally designed to cause variations in the larvae growth rate: (A) only artemia nauplii; (CD) only a commercial diet; (ED) only a semi-purified experimental diet; (ACD) and (AED) two treatments that involved weaning; and (S) starvation. Early weaning from artemia nauplii to the formulated diets (ACD and AED) affected growth and survival of the pacu larvae compared with the exclusive use of artemia (A). Starvation (S) and the commercial diet (CD) caused total mortality in pacu larvae at 18 dph. The experimental diet (ED) assured low fish survival and growth. The skeletal muscle morphology was not affected by the delay in somatic growth from early weaning onto the formulated diets. Three distinct muscle compartments were observed throughout the larval development in treatments A, ACD and AED: superficial, deep and intermediate, accompanied by muscle thickening. Severe undernourishment caused drastic differences in growth and in the morphology of the muscle fibers. Pacu larvae fed only formulated diets (CD and ED) showed muscle characteristics similar to the larvae in starvation (S) during the first 15 dph. At 27 and 35 dph, a slight increase in epaxial muscle mass was noted in larvae fed only the experimental diet (ED). At 35 dph, we observed a high frequency of fibers >= 40 mu m in the larvae that were weaned onto the formulated diets (ACD and AED), indicative of hypertrophy. In contrast, the larvae fed only artemia nauplii (A) displayed a larger number of fibers with diameters <= 20 mu m, which is indicative of hyperplasia. The expression of the MyoD and myogenin genes in pacu larvae at 35 dph was not affected by initial feeding (p>0.05). In conclusion, the formulated diets used impaired pacu larvae growth and survival; therefore, they were inadequate for pacu, at least at the times they were introduced. Artemia nauplii were the most adequate food source during first feeding of the pacu, and they produced bigger fish upon completion of the experiment. Moreover, the contribution of hyperplasia to the skeletal muscle growth appeared higher in fast- than in slow-growing pacu larvae. (C) 2011 Elsevier By. All rights reserved.

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Macrobrachium petronioi, a native Brazilian fresh-water shrimp, was captured along the coast of Rio Branco, Cananeia, São Paulo State, Brazil. The eggs were green-black in early development and the average size was 1.21 mm by 0.98 mm. Macrobrachium petronioi has no free-swimming larval phase. However, newly hatched larvae possessed several zoea I characters. Therefore, they were clearly more developed than newly hatched larvae of other species of Macrobrachium with prolonged larval development. The average duration of larval development in M. petronioi was 5.5 days. During early development, the larvae subsisted on stored yolk. After the third molt, the postlarvae accepted food. The three zoeal stages prior to the postlarval stage were described and characterized, with detailed morphological analyses. This species has a partially abbreviated type of development. The larval development of M. petronioi is distinguished from that of M. potiuna.

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Maternal antibody (MatAb) transfer is important for early chicken survivability. Diet composition and the amount of feed given to breeder pullets during rearing may affect the development of immunity and the transfer of MatAb to progeny, and could affect progeny performance and resistance to disease. The effects of broiler breeder nutrition and feeding management practices were evaluated for the transfer of MatAb to progeny and for spleen and bursa development at hatching in 2 genetic strains (A and B). In this experiment, the levels of MatAb against Newcastle disease virus were assessed by enzyme-linked immunosorbent assays in serum samples taken of pedigreed chicken progeny from hatching to 13 d of age. Chickens were fed corn-and wheat-based diets, as were their parents. The breeder feeding program and diet type altered the Newcastle disease virus MatAb found in progeny at hatching and affected how long these antibodies were maintained in circulation. Bursal follicle size at hatching was influenced by an interaction among all factors evaluated. Percentage of white pulp in the spleen was affected mainly by genetic strain and diet type, but responses varied according to the breeder feeding program. It was concluded that breeder feeding programs influence MatAb transfer and half-life, and may also affect the early development of lymphoid tissues.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)